The present invention relates to an improved method for generating a perspective graphic representation of a variable structure, such as a workpiece being processed in a numerically controlled machine tool, for example.
So-called CAD systems in general use today typically present a perspective graphic representation of an arbitrarily shaped body. However, in the past such perspective representations have been expensive to implement and have therefore found limited use in numerically controlled machine tools and related programming stations. Typically, such numerically controlled machine tools have in the past utilized a two dimensional representation of various views of the workpiece in order to assist in visualization by the operator.
Two prior art publications of interest include European Patent Application No. EP-A2-0 089 561 and European Patent Application No. EP-A2-0 089 562.
In addition, control systems such as that marketed under the trade name MAZATROL T-1 of the Yamazaki firm utilize three dimensional representations of a workpiece presented as a "transparent" wire model. Such transparent wire model representations can very quickly become difficult to use, since processing operations are generally represented only by the display of the center path of the tool.
The approaches to workpiece representation described above are not totally satisfactory, particularly when the graphic representation is used to check a previously programmed numerical control tool path for correction purposes.